The stock nv3500 5spd attached to the 4.3s and 4.8's have been rated to only handle upto 300ft/lbs of torque ( What I got by doing some research through google and talking to some shops ) There's a dude over in fullsizechevy.com forums thats running an 8.1 with a nv3500 thats lasted I think more then a few months and is using a 1ton clutch. They'll hold up but I wouldnt mash the gas and start chirping through the gears quick ( Can't really do that when its attached to a 4.3 nv3500's just suck ). I'm just going with a nv4500. Don't like autos all that much.

 

i have read through the posts and this great write up, but am wondering if it would be anymore difficult to do the swap on my 07. I can get my hands on a new lq4 longblock but no harness or pcm.. what other model harness and pcms can be used? Also will the 4l60or 65 it comes with bolt up for sure? If so i can build off of it instead of purchasing a new unit.
TIA
Miguel

 

ok i got a couple questions about this swap.

the 4.3 60e. that is not the same trans as the 60e that is in a v8?

the thorttle cable for the 4.3 will that work for the v8s or do u have to get a new one of those?

 

trannys are the same, except for one bolt on the top of the housing

throttle cable will work just attach it to the V8 bracket on the TB an go from there

 

you will want to stay around the same year on your harness an 06-07.you can re use your current pcm it need to be tuned for the lq4. you will also need a tac module along with harness and gas pedal, also a dbw TB make sure they come from the same year harness. 4l60 bolts right in, also use frame mounts and motor mounts from 2wd if your truck is a 2wd.

 

so 4wd mounts wont work on a 2wd truck?

 

its just on the frame mounts, motor mounts are the same. frame mounts bolt to the frame 2 long bolts and the drivers side is different on a 4wd truck. Motor mounts bolt to the frame mounts 3 bolts on each side

 

im dropping an 04 5.3 in my 03 silverado that currently has the 4.3. Am i going to need a new gas pedal to work with the electronic throttle body?

 

does ur 5.3 have drive by cable or drive by wire throttle body...in my cases the 4.3 has a db cable setup.....my 6.0l has a db wire setup....so i had to go out and get a dbw pedal and module along with the harness for the two of them!

not bad though i found a guy who has em for 55 plus shipping...let me know if u need one!

 

i just got back, grabbed the pedal, already have the harness, whats the module ur talkin about? the one on the firewall? if so i got that too